The stage and thread assembly known as the refeed, disclosed in co-pending U.S. patent application Ser. No. 08/734,632, the entire disclosure of which is herein incorporated by reference, had to singulate an envelope off a stack of ten to twenty envelopes and then present it to the threading roller for threading on the packing plate and insertion of material into the envelope. This design has a number of drawbacks.
For example, the stacking of envelopes prior to refeeding, in an area referred to as the understack, was very difficult to regulate at any constant height or number. This made it very difficult for the refeed apparatus to singulate an envelope therefrom with any consistency. Further, the prompter device which was used to pull envelopes off the top of the stack consisted of a threaded belt mounted above the stack. The prompter was turned on when it was time to pull an envelope from the stack; however, the belt often slipped on the envelope, thus missing the window of opportunity for the next insertion. Finally, the device which presented the envelope to the threading roller, known as the singulator, was very inconsistent in such presentation because the angle the envelopes entered the singulator varied due to an ever changing height of the stack of envelopes.